1. Field of Invention
This invention relates to variable bypass ratio turbojet engines and particularly to such engines and inverter flow valving to be used therewith which is light weight in construction, includes a minimal number of moving parts and no large moving parts, and which gives maximum bypass ratio variation possibility.
2. Description of the Prior Art
The prior art includes bypass engines, such as that shown in Sobey U.S. Pat. No. 3,016,698; Hewson U.S. Pat. No. 3,368,352; however, attempts to effect variable ratio bypass engines have produced results which are not fully satisfactory. For example, the engine shown in Schumacher et al U.S. Pat. No. 3,514,952 has variable ratio potential but has the disadvantage that, like Sobey and Hewson, it lacks provision for an auxiliary inlet and hence are not suitable for converting from high bypass ratio to low bypass ratio mode. U.S. Pat. No. 3,792,584 also discloses a variable bypass ratio engine which is a substantial improvement over the prior art but which has the disadvantage that it includes at least one large part which must be successfully mounted for rotation and which must be movably actuatable despite substantial inertia resistance. The inverter valve of this construction must be coaxial with the engine and annular in shape and presents the problems, such as sealing, of any new configuration in which a large part must be mounted for motion in a foreign environment.